Keyboard



FIG. 1 is a front perspective view of a keyboard showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a left side view thereof.

The broken line showing of unclaimed portions of the keyboard forms no part of the claimed design. 

The ornamental design for a keyboard, as shown and described. 